Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2014
Equity [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Rate, Percent	35.00%	35.00%		35.00%
Other Comprehensive Income (Loss), Net of Tax
Unrealized holding gains (losses) arising during the period. before tax	$ (1,608)	$ (24,545)		$ 29,643
Unrealized holding gains (losses) arising during the period, tax effect	563	8,591		(10,375)
Unrealized holding gains (losses) arising during the period, net of tax	(1,045)	(15,954)		19,268
Reclassification adjustment for (gains) losses included in net income	1,974	5,415		20
Reclassification adjustment for (gains) losses included in net income, tax effect	(691)	(1,895)		(7)
Reclassification adjustment for (gains) losses included in net income, net of tax	1,283	3,520		13
Effects on DAC and CCRA, before tax	(51)	328		(315)
Effects on DAC and CCRA, tax effect	18	(115)		110
Effects on DAC and CCRA, net of tax	(33)	213		(205)
Change in tax valuation allowance, before tax		0		0
Change in tax valuation allowance, tax effect		(42)		(21)
Change in tax valuation allowance, net of tax.		(42)		(21)
Other comprehensive income (loss), before tax	315	(18,802)		29,348
Other comprehensive income (loss), tax effect	(110)	6,539		(10,293)
Other comprehensive income (loss)	$ 205	$ (12,263)	$ 19,055	$ 19,055